Control handle with device advancing mechanism

ABSTRACT

A catheter having an internal advancing mechanism that can advance stiffening wires or other devices, has a catheter with a catheter body, a tip section distal the catheter body, a device extending through at least the catheter body, and a control handle proximal the catheter body, where the control handle has an advancing mechanism with a threaded member, an adjustment member, and a guided member to which the device is connected, and the advancing mechanism is configured to advance and retract the device along the catheter body as controlled by a user. Each of the threaded member and the adjustment member has a generally cylindrical configuration. The threaded member has an outer surface configured with a helical guide channel. The adjustment member is configured to guide the guided member to move within the helical guide channel to advance and retract the device. The adjustment member can be rotatable over the threaded member by the user to control advancement and retraction of the device. The device may be a stiffener wire, a needle or any other device suitable for advancement and retraction in a catheter.

FIELD OF INVENTION

The present invention relates to catheters, in particular,Electro-Physiology (EP) catheters with a control handle and a lumenedcatheter body.

BACKGROUND OF INVENTION

Catheter shafts are generally made of flexible, bio-compatible material,such as plastic, including polyethelene, polyester or polyamide.However, advancement into and through a patient's body and manipulationof a catheter can be difficult if the catheter shaft lacks a certainamount of stiffness. Moreover, it can be particularly challenging toprovide suitable flexibility, particularly near the shaft tip, whilemaintaining adequate overall shaft stiffness. While there are devicesavailable to provide or add stiffness to catheters, including stiffenerwires, they are typically separate and not integrated in the cathetersuch that separate handling and manipulation are required. Indeed, thereare few, if any, known mechanism internal to the catheter that canadvance stiffening wires or other devices into, or through, EPcatheters. It is therefore desirable to provide a catheter having aninternal advancing mechanism that can advance stiffening wires or otherdevices into or through the catheter shaft.

SUMMARY OF THE INVENTION

The present invention may be directed to a wide variety ofElectro-Physiology (EP) catheters (floppy shaft and/or multi-profile)that have applications for the advancement of a stiffening wire, needleor any other device. In one embodiment, there is provided a catheterwith a catheter body, a tip section and a device extending through atleast the catheter body, where a control handle has an advancingmechanism with a threaded member, an adjustment member, and a guidedmember therebetween to which the device is connected, to advance andretract the device along the catheter body as controlled by a user.

It is further provided that each of the threaded member and theadjustment member, both of which are generally cylindrical, are coupledto each other with the guided member between an inner surface of theadjustment member and an outer surface of the threaded member, with theguided member riding in a helical guide channel formed in the outersurface of the threaded member. The adjustment member is rotatable overthe threaded member by the user to move the guided member in the channelthereby controlling the advancement and retraction of the deviceattached to the guided member. Rotation in one direction advances thedevice along the catheter body and rotation in the opposition directionretracts the device. The device may be a stiffener wire, a needle or anyother device suitable for advancement and retraction in a catheter.

In a more detailed embodiment, there is provided a catheter having acatheter body, a tip section, a control handle comprising a threadedmember, an adjustment member mounted on the threaded member and a guidedmember situated therebetween, and a device connected to the guidedmember and extending distally therefrom through the control handle, thecatheter body and the tip section. The adjustment member is configuredfor rotation relative to the threaded member by a user to advance andretract the device. The device is wound about the threaded member andadapted to unwind and rewind as guided by the guided member in responseto rotation of the adjustment member relative to the threaded member bya user.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will bebetter understood by reference to the following detailed descriptionwhen considered in conjunction with the accompanying drawings wherein:

FIG. 1 is a side view of an embodiment of a catheter of the presentinvention.

FIG. 2 is a side cross-sectional view of an embodiment of a catheterbody, including the junction between the catheter body and a tipsection.

FIG. 3A is a side cross-sectional view of an embodiment of the tipsection, including the tip section, taken along a first diameter.

FIG. 3B is a side cross-sectional view of an embodiment of the tipsection, taken along a second diameter generally perpendicular to thefirst diameter.

FIG. 4 is a side cross-sectional view of an embodiment of a catheterhandle.

FIG. 5 is a longitudinal cross-sectional view of the catheter body ofFIG. 2, taken generally along line 5-5.

FIG. 6 is a longitudinal cross-sectional view of the tip section of FIG.2, taken generally along line 6-6.

FIG. 7 is a top view of the catheter handle.

FIG. 8 is a side cross-sectional view of an advancing mechanism and abarrel of the control handle.

FIG. 8A is a longitudinal cross-sectional view of the barrel of FIG. 8,taken along line a-a.

FIG. 8B is a longitudinal cross-sectional view of the barrel of FIG. 8,taken along line b-b.

FIG. 8C is a longitudinal cross-sectional view of the barrel of FIG. 8,taken along line c-c.

FIG. 8D is a longitudinal cross-sectional view of a threaded member ofFIG. 8, taken along line d-d.

FIG. 8E is a longitudinal cross-sectional view of the threaded member ofFIG. 8, taken along line e-e.

FIG. 8F is a longitudinal cross-sectional view of an adjustment memberof FIG. 8, taken along line f-f.

FIG. 8G is a longitudinal cross-section view of the adjustment member ofFIG. 8, taken along line g-g.

FIG. 9 is a cross-sectional view of a portion of the catheter tipsection showing a means for anchoring the puller wire.

FIG. 10 is a top cross-sectional view of a preferred puller wire anchor.

FIG. 11 is a side cross-sectional view of a preferred puller wireanchor.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, there is provided a catheter (for example, anElectro-Physiology (EP)) catheter 10 adapted to advance and retract adevice 46 (for example, a wire, a needle, infusion tube or the like) inthe catheter. The catheter comprises an elongated catheter body 12having proximal and distal ends, a tip section 14 at the distal end ofthe catheter body 12, and a control handle 16 having a threadedadvancing mechanism 17 controllable by a user to move the devicedistally and proximally in the catheter body.

With reference to FIGS. 2 and 5, the catheter body 12 comprises anelongated tubular construction having a single, central or axial lumen18. The catheter body 12 is flexible, i.e., bendable, but substantiallynon-compressible along its length. The catheter body 12 can be of anysuitable construction and made of any suitable material. Oneconstruction comprises an outer wall 22 made of a polyurethane or nylon.The outer wall 22 comprises an imbedded braided mesh of stainless steelor the like to increase torsional stiffness of the catheter body 12 sothat, when the control handle 16 is rotated, the tip section of thecatheter 10 will rotate in a corresponding manner.

The outer diameter of the catheter body 12 is not critical. Likewise thethickness of the outer wall 22 is not critical. The inner surface of theouter wall 22 is lined with a stiffening tube 20, which can be made ofany suitable material, for example, polyimide. The stiffening tube,along with the braided outer wall 22, provides improved torsionalstability while at the same time minimizing the wall thickness of thecatheter, thus maximizing the diameter of the single lumen. The outerdiameter of the stiffening tube 20 is about the same as or slightlysmaller than the inner diameter of the outer wall 22. Polyimide tubingmay be very thin walled while still providing very good stiffness. Thismaximizes the diameter of the central lumen 18 without sacrificingstrength and stiffness. Polyimide material is typically not used forstiffening tubes because of its tendency to kink when bent. However, ithas been found that, in combination with an outer wall 22 ofpolyurethane, nylon or other similar material, particularly having astainless steel braided mesh, the tendency for the polyimide stiffeningtube 20 to kink when bent is essentially eliminated with respect to theapplications for which the catheter is used

As shown in FIGS. 2 and 6, the tip section 14 comprises a short sectionof tubing 19 having three lumens. The tubing 19 is made of a suitablenon-toxic material which can be more flexible than the catheter body 12.One material for the tubing 19 is braided polyurethane, i.e.,polyurethane with an embedded mesh of braided stainless steel or thelike. The outer diameter of the tip section 14, like that of thecatheter body 12. The size of the lumens is not critical. In oneembodiment, the first lumen 30 and second lumen 32 are generally aboutthe same size, with the third lumen 34 having a slightly largerdiameter.

One embodiment of means for attaching the catheter body 12 to the tipsection 14 is illustrated in FIG. 2. The proximal end of the tip section14 comprises an outer circumferential notch 24 that receives the innersurface of the outer wall 22 of the catheter body 12. The tip section 14and catheter body 12 are attached by glue or the like. In thearrangement shown, a spacer 52 lies within the catheter body 12 betweenthe distal end of the stiffening tube 20 and the proximal end of the tipsection 14. The spacer 52 can be made of a material which is stifferthan the material of the tip section 14, e.g., polyurethane, but not asstiff as the material of the stiffening tube 20, e.g., polyimide. Aspacer made of Teflon® may be used in one embodiment. The spacer 52 mayhave an outer and inner diameter about the same as the outer and innerdiameters of the stiffening tube 20. The spacer 52 provides a transitionin flexibility at the junction of the catheter body 12 and catheter tip14, which allows the junction of the catheter body 12 and tip section 14to bend smoothly without folding or kinking.

The spacer 52 is held in place by the stiffening tube 20. The stiffeningtube 20, in turn, is held in place relative to the outer wall 22 by gluejoints at the proximal end of the catheter body 12.

As shown in FIGS. 2 and 5, extending through the single lumen 18 of thecatheter body 12 are lead wires 40, the device 46, a sensor cable 74,and a compression coil 44 through which a puller wire 42 extends. Asingle lumen 18 catheter body compared to a multi-lumen body can permitbetter tip control when rotating the catheter 10. The single lumen 18permits the lead wires 40, the device 46, the sensor cable 74, and thepuller wire 42 surrounded by the compression coil 44 to float freelywithin the catheter body. If such components were restricted withinmultiple lumens, they can tend to build up energy when the handle 16 isrotated, resulting in the catheter body 12 having a tendency to rotateback if, for example, the handle is released, or if bent around a curve,to flip over, either of which are often undesirable performancecharacteristics.

The puller wire 42 is anchored at its proximal end to the control handle16 and anchored at its distal end to the tip section 14. The puller wire42 is made of any suitable metal, such as stainless steel or Nitinol,and is coated with Teflon® or the like. The coating imparts lubricity tothe puller wire 42.

The compression coil 44 extends from the proximal end of the catheterbody 12 to the proximal end of the tip section 14. The compression coil44 is made of any suitable metal, such as stainless steel. Thecompression coil 44 is tightly wound on itself to provide flexibility,i.e., bending, but to resist compression. The inner diameter of thecompression coil 44 is slightly larger than the diameter of the pullerwire 42. The Teflon® coating on the puller wire 42 allows it to slidefreely within the compression coil 44. Along its length, the outersurface of the compression coil 44 is covered by a flexible,non-conductive sheath 26 to prevent contact between the compression coil44 and any of the lead wires 40, the device 46 or sensor cable 74. Anon-conductive sheath 26 made of polyimide tubing can be provided.

The compression coil 44 is anchored at its proximal end to the proximalend of the stiffening tube 20 in the catheter body 12 by a glue jointand at its distal end to the tip section 14 at a location distal to thespacer 52 by glue joint 50. Both glue joints may comprise polyurethaneglue or the like. The glue may be applied by means of a syringe or thelike through a hole made between the outer surface of the catheter body12 and the single lumen 18. Such a hole may be formed, for example, by aneedle or the like that punctures the wall of the catheter body 12 andthe stiffening tube 20 which is heated sufficiently to form a permanenthole. The glue is then introduced through the hole to the outer surfaceof the compression coil 44 and wicks around the outer circumference toform a glue joint about the entire circumference of the compression coil44.

As shown in FIGS. 2, and 6, the puller wire 42 extends into the secondlumen 32 of the tip section 14. The puller wire 42 is anchored to a tipelectrode 36 or to the side of the catheter tip section 14. Within thetip section 14, and distal to the glue joint 51, the turns of thecompression coil are expanded longitudinally. Such expanded turns areboth bendable and compressible. The puller wire 42 extends through theexpanded turns then into a plastic, such as Teflon®, sheath 81 (FIG.3B), which prevents the puller wire 42 from cutting into the wall of thetip section 14 when the tip section 14 is deflected.

As shown in FIG. 3B, the distal end of the puller wire 42 may beanchored to the tip electrode 36 by solder or the like, as shown in FIG.2 b or to the side wall of the tip section 14. If attached to the sidewall, an embodiment comprising an anchor 80 fixedly attached to thedistal end of the puller wire 42 is be used, as illustrated in FIGS.9-11. In such an embodiment, the anchor is formed by a metal tube 82,e.g., a short segment of hypodermic stock, which is fixedly attached,e.g., by crimping, to the distal end of the puller wire 42. The tube 82has a section which extends a short distance beyond the distal end ofthe puller wire 42. A cross-piece 84 made of a small section ofstainless steel ribbon or the like is soldered or welded in a transversearrangement to the distal end of the tube 82, which is flattened duringthe operation. This creates a T-bar anchor 80. A notch 86 is created inthe side of the catheter tip section 14 resulting in an opening into thesecond lumen 32 carrying the puller wire 42. The anchor 80 lies withinthe notch 86. Because the length of the ribbon forming the cross-piece84 is longer than the diameter of the opening into the second lumen 32,the anchor 80 cannot be pulled completely into the second lumen 32. Thenotch 86 is then sealed with polyurethane or the like to give a smoothouter surface.

With reference to FIGS. 3A and 3B, at the distal end of the tip section14 is a tip electrode 36. In the illustrated embodiment, the tipelectrode 36 has a diameter about the same as the outer diameter of thetubing 19. The tip electrode 36 is connected to the tubing 19 by meansof a plastic housing 21, which can be made of polyetheretherketone(PEEK). The proximal end of the tip electrode 36 is notchedcircumferentially and fits inside the distal end of the plastic housing21 and is bonded to the housing 21 by polyurethane glue or the like. Theproximal end of the plastic housing 21 is bonded with polyurethane glueor the like to the distal end of the tubing 19 of the tip section 14.

Mounted on the distal end of the plastic housing 21 is a ring electrode38. The ring electrode 38 is slid over the plastic housing 21 and fixedin place by glue or the like. If desired, additional ring electrodes maybe used and can be positioned over the plastic housing 21 or over theflexible tubing 19 of the tip section 14.

The tip electrode 36 and ring electrode 38 are each connected toseparate lead wires 40. The lead wires 40 extend through the third lumen34 of tip section 14, the catheter body 12, and the control handle 16,and terminate at their proximal end in an input jack (not shown) thatmay be plugged into an appropriate monitor (not shown). If desired, theportion of the lead wires 40 extending through the catheter body 12,control handle 16 and proximal end of the tip section 14 may be enclosedor bundled within a protective tube or sheath.

The lead wires 40 are attached to the tip electrode 36 and ringelectrode 38 by any conventional technique. Connection of lead wire 40to the tip electrode 36 can be accomplished by weld 43, as shown in FIG.3B. Connection of a lead wire 40 to a ring electrode 38 can beaccomplished by first making a small hole through the plastic housing21. Such a hole can be created, for example, by inserting a needlethrough the plastic housing 21 and heating the needle sufficiently toform a permanent hole. A lead wire 40 is then drawn through the hole byusing a microhook or the like. The ends of the lead wire 40 are thenstripped of any coating and soldered or welded to the underside of thering electrode 38, which is then slid into position over the hole andfixed in place with polyurethane glue or the like.

In the illustrated embodiment, a temperature sensing means is providedfor the tip electrode 36 and, if desired, the ring electrode 38. Anyconventional temperature sensing means, e.g., a thermocouple orthermistor, may be used. With reference to FIG. 3B, one temperaturesensing means for the tip electrode 36 comprises a thermocouple formedby an enameled wire pair. One wire of the wire pair is a copper wire 41,e.g., a number 40 copper wire which acts not only as part of thethermocouple, but as the electrode lead. The other wire of the wire pairis a construction wire 45, e.g., a number 40 construction wire, whichgives support and strength to the wire pair. The wires 41 and 45 of thewire pair are electrically isolated from each other except at theirdistal ends where they contact and are welded or soldered to the tipelectrode 36. Because it is desirable to monitor the temperature of thetip electrode 36 at a site adjacent the distal end of the optic fiber46, the thermocouple with a blind hole in the tip electrode 36 is fixedto the tip electrode 36 at the distal end of the blind hole as shown.The wires 41 and 45 extend through the third lumen 34 of the tip section14 and through the central lumen 18 of the catheter body 12 into thecontrol handle 16.

In the illustrated embodiment, an electromagnetic sensor 72 is containedwithin the distal end of the tip section 14. The electromagnetic sensor72 is connected by means of electromagnetic sensor cable 74, whichextends through the third lumen 34 of the tip section 14 and through thecatheter body 12 into the control handle 16. The electromagnetic sensorcable 74 comprises multiple wires encased within a plastic coveredsheath. In the control handle 16, the wires of the sensor cable 74 areconnected to a circuit board 64. The circuit board 64 amplifies thesignal received from the electromagnetic sensor and transmits it to acomputer in a form understandable by the computer. Also, because thecatheter is designed for single use only, the circuit board contains anEPROM chip which shuts down the circuit board after the catheter hasbeen used. This prevents the catheter, or at least the electromagneticsensor, from being used twice. A suitable electromagnetic sensor isdescribed, for example, in U.S. Pat. No. 4,391,199, which isincorporated herein by reference. An electromagnetic mapping sensor 72is manufactured by Biosense Ltd. Israel and marketed under the tradedesignation NOGA.

The electrode lead wires 40, thermocouple wires 41 and 45, andelectromagnetic sensor cable 74 and any other components or device,including the device 46, are allowed longitudinal movement within thecatheter body 12. The wires 40, 41 and 45 and cable 74 are allowed suchmovement so that they do not break when the tip section 14 is deflected.The device 26 is allowed such movement so that it can be advanced andretracted in accordance with a feature of the present invention. Toprovide for such lengthwise movement, there are tunnels provided throughthe glue joint 50 in the catheter body 12 (FIG. 2), which fixes theproximal end of the compression coil 44 inside the catheter body 12. Thetunnels are formed by transfer tubes 27, made of short segments ofpolyimide tubing in one embodiment. In the embodiment shown in FIG. 2,there is one transfer tube 27 for the wires 40, 41 and 45 and theelectromagnetic sensor cable 74 and a second transfer tube 27 for thedevice 46. It is understood that the number of transfer tubes may varyas desired.

Longitudinal movement of the puller wire 42 relative to the catheterbody 12, which results in deflection of the tip section 12, isaccomplished by suitable manipulation of the control handle 16. As shownin FIG. 4, the distal end of the control handle 16 comprises a piston 54with a thumb control 56 for manipulating the puller wire 42. Theproximal end of the catheter body 12 is connected to the piston 54 bymeans of a shrink sleeve 28.

The puller wire 42, lead wires 40, thermocouple wires 41 and 45, device46 and electromagnetic sensor cable 74 extend through the piston 54. Thepiston 54 lies within a barrel 57 of the control handle. The barrel 57is generally solid having a piston chamber for receiving the piston 54.Extending proximally from the piston chamber are two longitudinaltunnels 58 and 60 and a transverse hole 59 for receiving the anchor pin87. The first longitudinal tunnel 58 is in communication with thetransverse hole 59. The lead wires 40, thermocouple wires 41 and 45, andsensor cable 74 extend through the first tunnel 58. The puller wire 42also extends through the first tunnel 58 and is anchored to the anchorpin 87 in the transverse hole 59. The device 46 extends through thesecond tunnel 60. Between the distal end of the tunnels 58 and 60 andthe proximal end of the piston 54, chamber 62 provides additional spaceto avoid undesirable bending of the components extending therethrough.The electromagnetic sensor cable 74 connects to the circuit board 64 inthe control handle 16. Wires 90 connect the circuit board 64 to acomputer and imaging monitor (not shown).

The device 46, for example, a stiffener wire, a needle, or the like,extends through the control handle 16 and catheter body 12 and into thefirst lumen 30 of the tip section 14. In accordance with a feature ofthe present invention, the device 46 can be moved distally andproximally within catheter body by manipulation of the control handle16, as discussed further below. Where the device is a stiffener wire orthe like, the stiffener wire can be controlled to slide distally andproximally within the catheter body and/or tip section. Where the device46 is a needle or the like, its distal end can be advanced beyond thedistal end of the tip section to reach and contact tissue separatelyfrom the tip section, and then retracted back into tip section. Asunderstood by one of ordinary skill in the art, the device 46 is notlimited to stiffener wires and needles, but includes any structure thatmay be advanced within a catheter.

In the illustrated embodiment of FIGS. 4, 7 and 8, the control handle 16has a second barrel 55 proximal the barrel 57 for an extended controlhandle configuration. The device 46 extends proximally into the controlhandle through the piston 54 in the distal barrel 57, and through adistal end 100 of the proximal barrel 55 which has an opening or notch102 in its general circular cross section (FIG. 5 a) to accommodate thedevice 46. In the illustrated embodiment, the advancing mechanism 17, asmeans for allowing the advance and retraction of the device 46 inaccordance with a feature of the present invention, is mounted on aproximal end 104 of the proximal barrel 55.

In the illustrated embodiment, the device advancing mechanism 17includes a generally cylindrical threaded guide member 106, a generallycylindrical adjustment member 108 mounted thereon, and a guided member110 (e.g., a slug or pin) situated between an outer surface 114 of themember 106 and an inner surface 109 of the member 108. The guided memberslides in a helical guide channel 112, with a generally straight distalportion 116 and a generally straight proximal portion 118, all formed onthe outer surface 114 of the guide member 106. In the illustratedembodiment, the helical guide channel 112 winds about the guide member106 for approx. 4½ turns, such that the distal channel portions 116 and118 are generally diametrical of each other (see FIGS. 8 d and 8 e).

The generally cylindrical adjustment member 108 is sized such that itsinterior is in close conformity with the member 106 to receive thelatter in an overlapping, generally co-axial configuration. In thatregard, the guide member 106 has protrusions 120 that lock with arecessed ring 122 formed in the inner surface 109 of the proximal end ofthe adjustment member 108, for a snap-fit coupling. Radial alignment forproper assembly of the advancement mechanism is accomplished when anelongated slot 126 formed in the inner surface 109 of the distal end ofthe member 108 receives the guided member 110 situated in the channel112 of the member 106. As better illustrated in FIG. 7, the width of theslot is in close conformity to the width of the guided member 110 sothat rotation of the adjustment member 108 (shown in broken lines)effectively moves the guided member 110 in the channel 112 of the guidemember 106. Anchored to the guided member 110 is the proximal end of thedevice 46, the adjacent distal portion of which is wound about the guidemember 106 in the guide channel 112 and extends into the interior of thebarrel 55 from the generally straight distal channel portion 116 on themember 106.

As shown in FIG. 8, the distal end of the guide member 106 is insertedinto an enlarged conforming opening 130 at the proximal end of thebarrel 55 which has a generally cylindrical hollow interior 132. Withcoupling of the members 108 and 106, the advancement mechanism 17 formsa passage 133 that communicates with the interior 132 of the barrel 55and allows components, such as the lead wires 40, the electromagneticcable 74, and the thermocouple wires 41 and 45 extending proximallythrough the control handle to pass through the barrel 55. While thesecomponents extend through the interior 132 of the barrel 55, the device46 extends through similarly except toward the proximal end of thebarrel 55 which is provided with a passage 138 dedicated to the device46. Advantageously, the passage 138 is configured for alignment with thegenerally straight distal guide channel 116 of the guide member 106, sothat the device 46 can extend from the interior 132, through the passage138 and be wound onto the member 106.

To assemble the advancing mechanism 17 on the control handle, the guidedmember 110 with the proximal end of the device 46 anchored thereto isplaced in the channel 112 with the adjacent distal portion of the device46 wounded in the channels 112 and 116 distally therefrom. The distalend of the member 106 is inserted into the barrel 55. The member 108 isinserted distally over the member 106, with the slot 126 aligned withthe guided member 110, until the protrusions 120 of the member 106 lockin the ring recess 122 of the member 108 and the distal end of themember 108 generally abuts with the proximal end of the barrel 55.

In operation to accomplish the advancement and retraction of the device46, the advancing mechanism 17 can be manipulated by the user throughrotation of the adjustment member 108 by means of a knob 140 formed onan outer surface at the proximal end of the member 108. As the userrotates the knob (e.g. clockwise in the illustrated embodiment), theslot 126 on the inner surface 109 is rotated about the longitudinal axisof the member 108 to drive the guided member 110 helically along theguide channel 112 in the distal direction, which in turn distally pushesthe device 46 connected to the guided member 110. Such advancement cancontinue until the guided member 110 reaches the generally straightdistal guide channel 116, at which location the distal end of the slot126 blocks further distal movement of the guided member 110.

To retract the device 46, the user rotates the knob 140 in the oppositedirection (e.g., counterclockwise in the illustrated embodiment) whichcauses the slot 126 to drive the guided member 110 helically in theproximal direction, which in turn draws the device 46 proximally. Thisretraction can continue until the guided member 110 reaches thegenerally straight proximal guide channel 116, at which location theproximal end of the slot 126 prevents further proximal movement of theguided member 110.

It is understood by one of ordinary skill in the art that an overlappinglongitudinal region between the slot 126 and the helical guide channel112 defines the possible travel distance of the guided member 110 andthus the advancement/retraction distance of the device 46, and thereforevariations in either or both of the length of the slot and thelongitudinal spread of the channel 112 as between channels 116 and 118,and/or the degree of overlap can alter the travel distance of the guidedmember 110 and the maximum advancement/retraction distance of the device46. It is further understood that other variations, including a changein the diameter of the guiding member 106 (which changes thecircumference of the helical channel 112 and the maximumadvancement/retraction distance) and/or the number of windings or turnsof the helical channel can also alter the travel distance and maximumadvancement/retraction distance.

The illustrated embodiment of FIG. 3A discloses a needle as the device46, which can be advance beyond the distal end of the tip electrode 36.Clearly, as understood by one of ordinary skill in the art, the devicecan be other instruments or structures that need not extend beyond thedistal tip of the tip electrode when advanced to its maximum distalposition. Indeed, the amount of advancement and retraction desired orappropriate can be achieved with modifications of the advancementmechanism, including but not limited to the aforementioned variations.

The preceding description has been presented with reference to presentlypreferred embodiments of the invention. Workers skilled in the art andtechnology to which this invention pertains will appreciate thatalterations and changes in the described structure may be practicedwithout meaningfully departing from the principal, spirit and scope ofthis invention. For example, the advancing mechanism may be integratedanywhere along the control handle. User interface may be modified toallow for a linear motion deflection knob rather than the rotationalknob mentioned above.

Accordingly, the foregoing description should not be read as pertainingonly to the precise structures described and illustrated in theaccompanying drawings, but rather should be read consistent with and assupport to the following claims which are to have their fullest and fairscope.

1. A catheter comprising: a catheter body; a tip section distal thecatheter body; a device extending through at least the catheter body; acontrol handle proximal the catheter body, the control handle having anadvancing mechanism comprising a threaded member having a threaded outercircumference defining a channel, an adjustment member surrounding thethreaded member, and a guided member between the threaded member and theadjustment member, wherein the device is connected to the guided member,and wherein the adjustment member is configured to guide the guidedmember to move within the channel to wind and unwind the device in thechannel to thereby advance and retract the device along the catheterbody.
 2. A catheter of claim 1, wherein each of the threaded member andthe adjustment member has a generally cylindrical configuration, thechannel defined by the threaded outer circumference of the threadedmember is a helical guide channel.
 3. A catheter of claim 2, wherein theadjustment member is rotatable over the threaded member to therebycontrol advancement and retraction of the device.
 4. A catheter of claim1, wherein the device is a stiffener wire.
 5. A catheter of claim 1,wherein the device is a needle.
 6. A catheter of claim 1, wherein thedevice delivers fluid.
 7. A catheter of claim 1, wherein the adjustmentmember has a slot in its inner surface configured to guide movement ofthe guided member in the channel on the outer circumference of thethreaded member.
 8. A catheter of claim 1, wherein a distal end of theadvancing mechanism is located at a proximal end of the control handle,and the adjustment member is mounted over the threaded member.
 9. Acatheter of claim 1, wherein selected components extending through thecontrol handle extend through a passage within the adjustment member andthe advancing member.
 10. A catheter of claim 1, wherein the controlhandle has a dedicated passage through which the device passes toconnect with the guided member.
 11. A catheter of claim 1, wherein thecontrol handle has a thumb control in its distal region and theadvancing mechanism in its proximal region.
 12. A catheter comprising: acatheter body; a tip section distal of the catheter body; a controlhandle comprising an advancing mechanism having a threaded member havinga threaded outer circumference defining a channel, an adjustment membermounted onto the threaded member and a guided member situatedtherebetween; and a device connected to the guided member and extendingdistally therefrom through the control handle, the catheter body and thetip section, wherein the adjustment member is configured to guide theguided member to move within the channel to wind and unwind the devicein the channel to thereby advance and retract the device.
 13. A catheterof claim 12, wherein the adjustment member is configured for rotationrelative to the threaded member in one direction to advance the deviceand in an opposite direction to retract the device.
 14. A catheter ofclaim 12, wherein the device is a stiffener wire.
 15. A catheter ofclaim 12, wherein the device is a needle.
 16. A catheter of claim 12,wherein the device delivers fluid.
 17. A catheter of claim 12, whereineach of the threaded member and the adjustment members has a generallycylindrical configuration.
 18. A catheter comprising: a catheter bodyhaving an outer wall, proximal and distal ends and at least one lumenextending therethrough; a tip section comprising flexible tubing havingproximal and distal ends and at least one off-axis lumen, and optionallyat least one additional lumen, therethrough, the proximal end of the tipsection being fixedly attached to the distal end of the catheter body; acontrol handle comprising a threaded member having a threaded outercircumference defining a channel, an adjustment member mounted on thethreaded member and a guided member situated therebetween; and a deviceconnected to the guided member and extending distally therefrom throughthe control handle, the catheter body and the tip section, wherein theadjustment member is configured for rotation relative to the threadedmember to thereby guide the guided member to move within the channel towind and unwind the device in the channel to thereby advance and retractthe device.
 19. A catheter of claim 18, wherein a proximal portion ofthe device is wound about the threaded member and adapted to unwind andrewind following movement of the guided member in response to rotationof the adjustment member relative to the threaded member by a user. 20.A catheter of claim 18, wherein the device is a stiffener wire.
 21. Acatheter of claim 18, wherein the device is a needle.
 22. A catheter ofclaim 18, wherein the device is configured for tissue contact separatelyfrom the tip section.